Diversity antenna apparatus of mobile terminal and implementation method thereof

ABSTRACT

Provided is a diversity antenna apparatus of a mobile terminal including a main antenna and a sub-antenna for performing an auxiliary function using a separate sub-antenna processing module, and an implementation method thereof. When the auxiliary function is not performed, a controller of the mobile terminal disconnects the sub-antenna from the sub-antenna processing module and electrically connects the sub-antenna to an RF module through a switch such that the sub-antenna operates as a diversity antenna.

PRIORITY

This application is a continuation application of U.S. patentapplication Ser. No. 11/852,093, which was filed in the U.S. Patent andTrademark Office on Sep. 7, 2007, which claims priority under 35 U.S.C.§119(a) to a Korean Patent application filed in the Korean IntellectualProperty Office on Sep. 7, 2006 and assigned Serial No. 2006-86078, thecontents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an antenna apparatus of amobile terminal, and in particular, to a diversity antenna apparatus forenabling a sub-antenna used for an auxiliary function to selectivelyoperate as a diversity antenna without a separate diversity antenna,thereby achieving a size reduction of the mobile terminal, and animplementation method of the diversity antenna apparatus.

2. Description of the Related Art

A mobile terminal generally uses various frequencies. Also, in themobile terminal, a fading phenomenon, in which a Transmit/Receive(Tx/Rx) signal level fluctuates according to external environments,frequently occurs. A diversity antenna apparatus is used to preventdeterioration of Tx/Rx characteristics due to the fading phenomenon.

The diversity antenna apparatus, which transmits/receives a signal usingtwo antennas, enables only one antenna in a high electric field region,and enables two antennas at the same time in a low electric fieldregion, or when the operational environment surrounding user's mobileterminal deteriorates due to his movement, thereby preventing thedeterioration of Tx/Rx sensitivity of the mobile terminal.

However, as described above, because the diversity antenna apparatusincludes two antennas installed in the mobile terminal, the apparatusgoes against a current slimness trend of mobile terminals.

SUMMARY OF THE INVENTION

An object of the present invention is to substantially solve at leastthe above problems and/or disadvantages and to provide at least theadvantages below. Accordingly, an object of the present invention is toprovide a diversity antenna apparatus and an implementation method ofthe diversity antenna apparatus, for enabling a pre-installedsub-antenna, which is used for an auxiliary function, to selectivelyoperate as a diversity antenna, thereby eliminating the need for aseparate diversity antenna.

Another object of the present invention is to provide a diversityantenna apparatus and an implementation method of the diversity antennaapparatus, for enabling a pre-installed sub-antenna to selectivelyoperate as a diversity antenna, thereby preventing increase in size ofthe mobile terminal due to the additional installation of a separatediversity antenna.

Still another object of the present invention is to provide a diversityantenna apparatus and an implementation method of the diversity antennaapparatus, for preventing the additional installation of a separatediversity antenna and the size increase of the mobile terminal, therebyachieving cost reduction and call quality improvement in the mobileterminal.

According to one aspect of the present invention, a diversity antennaapparatus includes a main antenna, a sub-antenna for performing anauxiliary function of the mobile terminal, the sub-antenna operating ina frequency band identical or similar to a frequency band for the mainantenna, a first Radio Frequency (RF) module for transmitting/receivinga signal through the main antenna, a second RF module installedseparately from the first RF module, a sub-antenna processing module fortransmitting/receiving a signal through the sub-antenna, a switchprovided on a feed line of the sub-antenna, for selectively connectingthe second RF module or the sub-antenna processing module to thesub-antenna, and a controller for controlling the switch in accordancewith the operation state of the mobile terminal and enabling thesub-antenna to selectively operate as a diversity antenna of the mobileterminal.

According to another aspect of the present invention, a method forimplementing a diversity antenna apparatus of a mobile terminalincluding a main antenna and a sub-antenna for performing an auxiliaryfunction using a sub-antenna processing module, the method includesdisconnecting, at a controller of the mobile terminal, the sub-antennafrom the sub-antenna processing module to electrically connect thesub-antenna to an RF module through a switch such that the sub-antennaoperates as a diversity antenna when the auxiliary function is notperformed.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription when taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is a perspective view of a mobile terminal including a Bluetooth®(hereinafter “Bluetooth”) module according to the present invention; and

FIG. 2 is a block diagram of a mobile terminal according to the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described hereinbelow with reference to the accompanying drawings. In the followingdescription, well-known functions or constructions are not described indetail since they would obscure the invention in unnecessary detail.

FIG. 1 is a perspective view of a mobile terminal including a Bluetoothmodule according to the present invention. FIG. 1 illustrates a mobileterminal 100 and a Bluetooth device 10 for wireless communication in 2.4GHz band. Thus, a main board (not shown) installed in the mobileterminal 100 includes a main antenna for the signaltransmission/reception of the mobile terminal, and a Bluetooth modulefor wireless communication with the Bluetooth device 10. The mainantenna, the Bluetooth module, and a Bluetooth antenna may be mounted onthe main board in a plate type, a chip set type, and a known chipantenna type, respectively.

However, a sub-antenna according to the present invention is not limitedto the Bluetooth antenna, and various sub-antennas corresponding tomodules for performing auxiliary functions may be mounted. Thesub-antennas may be installed in the mobile terminal and operate invarious bands. For example, the present invention includes a mainantenna applied to a Universal Mobile Telecommunications System (UMTS)2100 type terminal operating in 2.1 GHz band, so that sub-antennas,which correspond to the Bluetooth module, a Wireless Broadband (WiBro)module, a Wireless Local Loop (WLL) module, and a Wireless Fidelity(WiFi) module operating in similar band to the 2.1 GHz band, can beused.

FIG. 2 is a block diagram of a mobile terminal according to the presentinvention. In this mobile terminal, a controller 201 includes a modemfor processing Tx/Rx signals of first and second RF modules 202 and 203,respectively. The first and second RF modules 202, 203 may be designedinto a single RF module that can separately process Tx/Rx signals withrespect to respective antennas.

A main antenna 230 according to the present invention is electricallyconnected to the first RF module 202 that processes Tx/Rx signals withrespect to the main antenna 230. A sub-antenna 240 is electricallyconnected to the second RF module 203 or a Bluetooth module 204 througha switch 220. The switch 220 is controlled by the controller 201 and maybe implemented using a known Single Pole, Double Throw (SPDT) switch.

The controller 201 can automatically control the switch 220 according toa use environment of the mobile terminal. For example, when the mobileterminal performs a Bluetooth function, the controller 201 controls theswitch 220 such that the sub-antenna 240 is connected to the Bluetoothmodule 204. However, when the mobile terminal does not perform theBluetooth function, the controller 201 controls the switch 220 such thatthe sub-antenna 240 is connected to the second RF module 203 and thesub-antenna 240 can operate as a diversity antenna.

A matching circuit 221 may be provided on a feed line between the switch220 and the second RF module 203. Similarly, a matching circuit 222 maybe provided on a feed line between the switch 220 and the Bluetoothmodule 204. The matching circuits 221 and 222 may be constructed usingpassive elements such as an inductor and a capacitor. Consequently, thematching circuit 221 may be used for frequency matching corresponding toa frequency used by the sub-antenna 240 operating as the diversityantenna, and the matching circuit 222 may be used for frequency matchingcorresponding to a frequency used by the sub-antenna 240 operating asthe Bluetooth antenna.

Preferably, a difference between frequency bands used by the mainantenna 230 and the sub-antenna 240 is less than or equal to f/8, wheref is the frequency band of the main antenna. For example, when the mainantenna 230 of FIG. 2 operates in 2.1 GHz band as a UMTS 2100 RX band,it is preferable that the frequency band of the sub-antenna 240 is notmore than approximately 260 MHz greater than or less than the 2.1 GHzband.

Thus, it is preferable that the sub-antenna 240 is set to operate in2.25 GHz band between the 2.4 GHz band used by the Bluetooth antenna andthe 2.1 GHz band used by the main antenna. That is, under the control ofthe switch 220, the sub-antenna 240 using 2.25 GHz band operates as thediversity antenna using the 2.1 GHz band or the Bluetooth antenna usingthe 2.4 GHz band through the matching circuit 221 or the matchingcircuit 222, respectively.

However, the method of using the matching circuit according to thepresent invention is not limited to the specific case described above.For example, the sub-antenna 240 may be set to operate in the frequencyband used by the Bluetooth antenna, and a matching circuit is providedonly on the feed line between the sub-antenna 240 and the second RFmodule such that the matching circuit performs frequency matching onlywhen the sub-antenna 240 is used as the diversity antenna.

A display unit 205, a memory unit 206, a COder-DECoder (CODEC) 207, akey input unit 208, a microphone 211, and a speaker 210 are well-knowncomponents, and thus their description will be omitted for conciseness.

The antenna apparatus according to the present invention can allow thesub-antenna, which is used for the auxiliary function, to selectivelyoperate as the diversity antenna, so that it does not require a separatediversity antenna. Therefore, saving space and reducing cost, and highquality mobile terminal production, due to the improvement of Tx/Rxsensitivity, can be implemented.

While the invention has been shown and described with reference tocertain preferred embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims.

1-14. (canceled)
 15. A portable communication device comprising: a firstantenna adapted to support a cellular communication; a second antennaadapted to support a wireless local area communication including a firstwireless local area communication and a second wireless local areacommunication; first circuitry adapted to support the cellularcommunication; second circuitry adapted to support the first wirelesslocal area communication; third circuitry adapted to support the secondwireless local area communication; and a processor configured to:identify a request for a function; couple the second antenna with thesecond circuitry based on at least a first determination that thefunction corresponds to a first specified function; couple the secondantenna with the third circuitry based on at least a seconddetermination that the function corresponds to a second specifiedfunction; and perform, in response to the request for the function, thefunction using a corresponding one of the second circuitry and the thirdcircuitry coupled with the second antenna.
 16. The portablecommunication device of claim 15, wherein the processor is furtherconfigured to: perform the identifying while the cellular communicationis established between the portable communication device and an externalelectronic device.
 17. The portable communication device of claim 15,wherein the processor is further configured to: selectively couple thefirst antenna with one of the second circuitry and the third circuitrybased on at least the request for the function.
 18. The portablecommunication device of claim 15, wherein the processor is furtherconfigured to: perform the coupling of the second antenna with one ofthe second circuitry and the third circuitry while the first antenna iscoupled with the first circuitry.
 19. The portable communication deviceof claim 15, wherein the controller is further configured to: one ofreceive and transmit a cellular signal via the first antenna and abluetooth signal via the second antenna.
 20. A portable communicationdevice comprising: first circuitry adapted to support a cellularcommunication; second circuitry adapted to support a first wirelesslocal area communication; third circuitry adapted to support a secondwireless local area communication; a first antenna adapted to be coupledwith the first circuitry; and a second antenna adapted to be selectivelycoupled with one of the second circuitry and the third circuitry. 21.The portable communication device of claim 20, wherein the first antennais physically connected with the first circuitry.
 22. The portablecommunication device of claim 20, further comprising a switch adapted toselectively couple the second antenna with one of the second circuitryand the third circuitry.
 23. The portable communication device of claim22, further comprising a controller adapted to control the switch. 24.The portable communication device of claim 23, wherein the controller isconfigured to: operate the first antenna as a diversity antenna withrespect to the function.
 25. The portable communication device of claim22, further comprising a matching circuit adapted to adjust a frequencyto be used by one of the first antenna and the second antenna.
 26. Aportable communication device comprising: an antenna; first circuitryadapted to support a first wireless local area communication using afirst frequency band; second circuitry adapted to support a secondwireless local area communication using a second frequency band; and aprocessor configured to: identify a request for a function; couple theantenna with the first circuitry based on at least a first determinationthat the function corresponds to a first specified function; couple theantenna with the second circuitry based on at least a seconddetermination that the function corresponds to a second specifiedfunction; and perform, in response to the request for the function, thefunction using a corresponding one of the first circuitry and the secondcircuitry coupled with the antenna.
 27. The portable communicationdevice of claim 26, wherein the controller is further configured to:identify a frequency band to be used with respect to the function;perform the first determination if the frequency band corresponds to thefirst frequency band; and perform the second determination if thefrequency band corresponds to the second frequency band.
 28. Theportable communication device of claim 26, wherein the first specifiedfunction comprises one of a bluetooth function, a wireless fidelityfunction, and a combination thereof, and the second specified functioncomprises one of a wireless local loop function, a global positioningsystem function, a near field communication function, and a combinationthereof.
 29. A portable communication device comprising: first circuitryadapted to support a first wireless local area communication; secondcircuitry adapted to support a second wireless local area communication;and an antenna adapted to be selectively coupled with one of the firstcircuitry and the second circuitry.
 30. The portable communicationdevice of claim 29, further comprising a switch adapted to selectivelycouple the antenna with one of the second circuitry and third circuitry.31. The portable communication device of claim 29, further comprising aprocessor adapted to control the switch.
 32. The portable communicationdevice of claim 29, further comprising third circuitry adapted tosupport a cellular communication and another antenna adapted to becoupled with the third circuitry.
 33. The portable communication deviceof claim 32, wherein the another antenna is physically connected withthe third circuitry.
 34. The portable communication device of claim 29,wherein the first wireless local area communication comprises one of abluetooth communication and a wireless fidelity communication, and thesecond wireless local area communication comprises one of a near fieldcommunication and a wireless local loop communication.